This invention relates to fishing apparatus, particularly of the type used in sport fishing where, in order to troll at depth levels of fifty to perhaps two hundred feet or more, a heavy weight at the end of a small winch cable (usually called a "downrigger") is used to sink a lure-carrying trolling line to the desired depth, and to maintain it at such depth. Typically, the fishing line is releasably attached to the weighted downrigger line so that when a strike occurs the fishing line releases from the downrigger cable, leaving only the fish and lure attached to the fishing line, and freeing the latter from the heavy downrigger weight (which remains attached to the downrigger cable), for greater sporting action.
Typically, such trolling equipment is used by having a permanently-mounted fitting in the downrigger line, usually at its bottom, near the weight, to which the fishing line is clipped or otherwise fastened, and thereby attached to the downrigger cable. For example, U.S. Pat. No. 3,778,918 shows a device with a ring at each end for direct attachment to the downrigger line at one end and the downrigger weight at the other end, with a medial portion of the device adapted to receive a pair of spaced, springloaded legs which form the release clip which is pulled away by the force of a strike to free the fishing line from the weight.
In such an arrangement, only a single fishing line can be used with each downrigger, and this has numerous disadvantages. In the first place, it is desirable to use a number of different fishing lines, each on its own fishing rod and reel, at varying depths, in order to cover a larger depth range while trolling, to thereby increase the chance of encountering fish; however, the downrigger units are expensive and if purchased in numbers equalling the desirable number of fishing lines the expense would be more than most fisherman would find agreeable. Further, there is not sufficient space on many, or even most, fishing boats to accommodate such a large number of downrigger units, even if expense were no objection; in fact, even a fairly small number of downrigger units becomes a problem as a result of the clutter of equipment so produced.
It has been proposed to attach multiple fishing lines to a single downrigger cable, but no really effective means for doing this has heretofore been provided. For one thing, the position of attachment should not be permanently fixed along the length of the downrigger line, but should instead be variable in order to permit adjustment and variations in the spacing between different fishing lines; however, it is very important that the attachment not slip along the downrigger cable despite the fact the attachment is totally submerged and used at considerable depths under water, and must withstand the forces resulting from being towed through the water while pulling a long length of trolled line carrying a dodging or otherwise moving lure at the end, which also exerts either an upward or downward pulling effect, depending upon buoyancy characteristics. Furthermore, the attachment absolutely must not kink or otherwise damage the downrigger line, which is typically a stranded metal cable, since otherwise the resulting stress concentration at such a point would result in breakage of the downrigger cable and loss of equipment.